2004 Honda Accord DX (4-cyl, manual) decelerates at 3000rpm

I have a 2004 Honda Accord (4 cylinder, manual) with about 150,000 miles. Yesterday it started acting up. For the first 10 or 15 minutes I drive it, it is fine, but then as soon as I hit about 2900 or 3000 rpm the car violently hiccups as if I just slammed on the brakes once and then begins to decelerate. It does not matter what gear I am in, so long as I hit 2900 or 3000 rpm it does the same thing. Now if I shift to a higher gear and am trying to accelerate, it will be fine until I hit 2900 or 3000 rpm again. If I keep pushing on the gas after it hiccups, it doesn’t continue to jerk but it continues to decelerate.

Now if I am in neutral (I have tested this in my driveway), it doesn’t hiccup but it will decelerate once I hit 2900 or 3000 rpm. Even if I push on the gas harder as it is doing this, the tachometer continues to drop.

I tried to add some fuel injector cleaner to the gas tank in hopes that I had a plugged fuel injector, but it is still acting up.

I should also mention that the check engine light is on.

Any thoughts?!?!?!

The problem might be with a restricted catalytic converter. Since the Check Engine light is on, pulling the codes will confirm if it’s a problem with the cat.


Please go get the computer error code(s) read and post it here.
Post the code number. It will look like P0123.
Some places like AutoZone will read it for free.